1. Field of the Invention
This invention relates generally to penetrating agents which are applied to seized, rusted, or corroded metal parts to free them by seeping into the minute cracks separating the parts and dissolving any corrosion present. More particularly, this invention relates to such a penetrating agent that has dissolved in it a siloxane polymer which is carried into the cracks and is left to coat the parts after the penetrant has volitalized. The siloxane polymer lubricates the parts and prevents further corrosion.
2. Prior Art
Penetrating agents are commonly used to free metal parts such as nuts, bolts, machine screws, shafts, and similar parts that have become corroded and are "frozen". Many of these penetrating agents, along with compounds intended strictly for lubrication, include a siloxane polymer or some other silicone ingredient to give the formula additional lubricating properties. U.S. Pat. Nos. 3,468,688 (Mitachek), 3,928,218 (Rowe), and 4,059,534 (Morro) all describe lubricating formulas composed of a silicone fluid and a hydrocarbon oil having a relatively high viscosity in order to give good lubricating properties.
Penetrating oils making use of silicone fluids are disclosed in U.S. Pat. Nos. 2,467,178 (Zimmer), and 3,578,596 (Conway). Zimmer calls for a silicone polymer, an aromatic hydrocarbon oil, and a surfactant ingredient such as tricresyl phosphate to reduce the surface tension of the composition and so enhance its penetrating ability. Conway likewise uses a hydrocarbon oil as a carrier for a silicone polymer and includes an alkyl ester of carboxylic acid which serves as a surfactant.
By using hydrocarbon oils as the carrier for the silicone ingredient, these known penetrating oils absolutely require a surfactant additive to lower the formula's surface tension so that it can effectively penetrate into corroded parts.